which gives me a nice plot with legend. However, as you can see, the "\!(*OverscriptBox[(QBER), (^)])" appears twice, in FLB and FUB. If I put 'None' instead of the second "\!(*OverscriptBox[(QBER), (^)])" for example, the legend will desappear, but the plot mark for "\!(*SubscriptBox[(QBER), (UB)]), Eq. (8)" will appear as dot instead of a dash. Anyone knows how to delete the duplicated legend and keep the next ones okey?

Unfortunately it is not working yet. Right now I cannot share the full code, since it is part of a working paper. However I'll try to share the maximum information that I can in order for you to be able to help me.

and you can see the fourth line of the legend is equal to the second (inside the red box).

However if I use what you suggest and which I have tryed before I get the following:

As you can see inside the repeated legend is now longer there, however I have another problem, which is: the plot mark is a dot instead of a dash. The only thing that I changed was "\!\(\*OverscriptBox[\(QBER\), \(^\)]\)" to None in FUB. How did he changed the dash to dot? How can I get the dash is it is plotted?

So, this is the main problem that I have here. Based on what I just provided, can you find a solution for it?